Humans use senses, such as hearing, sight, taste, smell and touch, to perceive and understand the real world. Human brains and nervous systems are capable of processing signals from all the senses, selecting important signals to pay attention to and ignoring unimportant signals, at least at information rates that are common in real-world situations.
Modern society has developed rich parallel virtual worlds, full of digital data. In some cases, the virtual worlds represent real or fictional environments in which people, animals or avatars reside and interact. Virtual reality (“VR”) goggles are sometimes used to present a virtual world to a human user, however VR goggles occlude the real world from the human user. Some VR systems include a view of the real world in their displays. However, these views are rendered through the filter of the VR system, for example using the VR system's camera and image processing circuit, and are, therefore, necessarily different from what the human user would see with her own eyes. Similar goggles are used by pilots who control drone aircraft. Such goggles provide views of only the real world, albeit through the filter of the drone's camera.
In some cases, humanly-imperceptible data about real-world objects or environments is useful to “overlay” over the real world. Google glass head-mounted display displays information, such as weather forecasts, about a location in which a user wears the device, thereby providing an augmented reality (“AR”) view of the real world. AR devices permit a human user to view the real world with her own eyes, but with digital data overlaid over the view of the real world.
However, in general, conventional VR and AR technologies have problems related to intermodal “distance” between the real world's presentation and the virtual (digital) world's presentation. The virtual world may be too conceptually far from the real world and, therefore, the virtual world may distract the user's attention from the real world. Indeed, some VR systems are designed to provide distracting entertainment. In other cases, the virtual world may be rendered too close and, therefore, occlude the real world, such as by masking it or making it confusing.
Humans often face situations in which useful digital information is available, but the humans are unable to absorb the information and effectively make decisions based on the information due to sensory or cognitive overload, such as in high-stress contexts, for example in combat. In some cases, a given sense, such as vision, needs to be dedicated to a high-priority task, such as driving a car, and is, therefore, not available to receive digital information, such as a text message or to read a briefing paper ahead of a meeting to which the user is driving. Although VR and AR systems are touted as tools for alleviating such information overload problems, conventional systems have failed to adequately do so.